Breathing the gas from your BCD

[LI-er]

One freak death from a guy who breathed from a moldy BCD, his own.

Emergency Breathing from Your BCD: Undercurrent 06/2011

Ok so the danger is clearly over rated. Still I'd never empty a BCD that way just I make a negative entry. But taking "up to 13 recycled breaths" as a recommended maximum per the article could save an OOA diver who has no alternative.

 

[scubadada]

This has been discussed many times on ScubaBoard. It is hard to conceive of a scenario where this makes sense. If you are OOA in the open water and have no alternate air source available, then your choices are the CESA or the buoyant ascent. Both of them call for you to be exhaling all the way to the surface.

In this thread, @LI-er asks about emptying your BC for a quick, negative descent.

Head down, butt up, pull the rear dump, quick and easy.

 

[boulderjohn]

Ok so the danger is clearly over rated. Still I'd never empty a BCD that way just I make a negative entry. But taking "up to 13 recycled breaths" as a recommended maximum per the article could save an OOA diver who has no alternative.

Please describe a hypothetical situation in which you would do that.

 

[Badger7]

I've sucked the last bit of air out of wings, ziplock bags, smbs, air mattresses, you name it. In all cases, I'm just using volume in my mouth to pull a vacuum, not sucking in with my lungs. Bacteria aside, I wouldn't want to inhale any sea or lake water. You'd need a pretty heinous strain of bacteria to be growing in your BCD to cause infection from just incidental mouth contact, and if so, it means you are doing a terrible job of rinsing out your gear with fresh water after the day's diving is complete.

That said, yeah no need for it as previously stated. Before you go on the boat, just fully submerge your BCD in the rinse tank and hold the inflation valve open above the water and you'll get rid of 99% of any gas volume.

I'd be far more concerned about the entire group managing their equalization on a "hot drop" like that. The pint of air left in your BC should be nothing compared to the 5lbs negative weight of a full cylinder of gas, and if you're REALLY concerned just add a pound or two of lead until you're comfortable with the whole procedure before giving yourself pneumonia doing a vacuum pack of your BC.

 

[boulderjohn]

In this thread, @LI-er asks about emptying your BC for a quick, negative descent.

Head down, butt up, pull the rear dump, quick and easy.

I was replying to a post calling for the use of a BCD to supply air in an emergency. I understand that it is different from the original question of the thread.

 

[tursiops]

Why? Unnecessary work.

Because the tank cam straps stretch when they get wet...it is why tanks get loose.

 

[Blackcrusader]

In this thread, @LI-er asks about emptying your BC for a quick, negative descent.

Head down, butt up, pull the rear dump, quick and easy.

That's how we do it in South Lombok in the foamy water. Also add an extra kilo or two if you need.

 

[LI-er]

Please describe a hypothetical situation in which you would do that.

A hypothetical scenario where I might recycle the breaths inside my BCD to try to save my life would be going deep inside a deep wreck on a single AL80, getting lost and draining the tank. With no other option I'd recycle the air in my bcd until I either found my way out and surfaced, ran into an alternate air source such as another diver, or passed out and drowned.

 

[LI-er]

Because the tank cam straps stretch when they get wet...it is why tanks get loose.

Ok makes sense but it's not common practice, it's more work and tanks falling out of BCDs isn't an every day thing.

 

[tursiops]

Ok makes sense but it's not common practice, it's more work and tanks falling out of BCDs isn't an every day thing.

It is common enough that how to reinsert (while underwater) a loose tank into the cam straps got included in the PADI OW course in 2013.

(Orig post said 2017; typo. The date was 2013, mandatory use in 2014 InstructorsManual.)